

Well the electrolyte solution is water based so exceeding the boiling point will cause pressure buildup inside.
Edit: hmm seems I might be generalizing too much. Not all batteries use water based solutions. My point is that you should avoid a pressure buildup inside the battery due to reaching the solvents’ boiling point.
Good point. It’s highly concentrated inside a battery if not saturated. Hmm. I still wouldn’t expose them to such high temperatures.
Perhaps a longer duration at lower temperature is safer. I might try it some day with some waste batteries and a battery tester.